> diff --git a/include/uapi/linux/perf_event.h b/include/uapi/linux/perf_event.h > index 9de8780..ec97a70 100644 > --- a/include/uapi/linux/perf_event.h > +++ b/include/uapi/linux/perf_event.h > @@ -372,7 +372,8 @@ struct perf_event_attr { > context_switch : 1, /* context switch data */ > write_backward : 1, /* Write ring buffer from end to beginning */ > namespaces : 1, /* include namespaces data */ > - __reserved_1 : 35; > + no_counter : 1, /* no counter allocation */ Not sure we really want to expose this in the user ABI. Perhaps make it a feature of the in kernel API only? -Andi